skip to main content

Starling Forces — FRCA Primary MCQ

Instant feedback + full explanation. One question, done properly.

HardPhysiology - CardiovascularStarling ForcesFRCA Primary

Which set of variables constitutes the classic Starling forces across a systemic capillary wall?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Capillary hydrostatic pressure, interstitial hydrostatic pressure, plasma oncotic pressure, and interstitial oncotic pressure

The best answer is “Capillary hydrostatic pressure, interstitial hydrostatic pressure, plasma oncotic pressure, and interstitial oncotic pressure”. The classic Starling formulation describes fluid flux using hydrostatic pressure in the capillary and interstitium, together with oncotic pressure in plasma and interstitium. Capillary hydrostatic pressure favours filtration, whereas plasma oncotic pressure favours absorption. The reflection coefficient and filtration coefficient modify the relation but are not themselves four pressures.

Reference: Royal College of Anaesthetists, Primary FRCA Syllabus 2021: https://www.rcoa.ac.uk/sites/default/files/documents/2026-01/Primary-FRCA-Syllabus.pdf